Best available cop x



Feb. 28, 1928.

E. B. THURSTON CONTROL SYSTEM FOR ELECTRIC ELEVATORS Fil ed May 8. 1922 2 Sheets-Sheet 1 ATTEIRNY Feb. 28, 1928. 1,661,021

E. B. THURSTON CONTROL SYSTEM FOR ELECTRIC ELEvAToRs Filed May 8. 1922 2 Sheets-$156912.

7 l /scl a7 d 2 52% me Patented Feb. 28, 1928.

UNITED STATES PATENT OFFICE.

ERNEST B. THURSTON, OF TOLEDO, OHIO, ASSIGNOR TO THE HAUGHTON ELEVATOR & MACHINE CO., OF TOLEDO, OHIO, A CORPORATION OF OHIO.

CONTROL SYSTEM FOB LECTRIC ELEVATORS.

Application tiled May 8,

This invention relates to features of'a'lternating electric current elevator control :and operation. Y

This invention' has utility when incorporated in elevators-'wherein polyphase alternatingelectric current is used in connection withtwo speed motors'and the controlfdevices therefor. l

Referring'to the drawings: 'L

Fig. 1 Ais an"'aeiossthel'ne'-,diagram fof a wiring layfout embodyingithe invention, :the reference characters in parenthesis indieating theA operator,` `for the` swiltc'hpadjacent which s uch reference character parenthesis is placed.r j; y

Fig. 2 is a wiring diagram of the I'features thereof, the switches on ,the controll board` being in the reverse directionor as looking at the back from Fig. 1

In a `b uildin structure there is herein shown as Drovic ed an elevator .shaft or elevator well `1 having a plurality f'landings lor floors 2 past which or to which'the e levator car 3 is operable -in this shaft 1.` This elevatorcar in its travel is handled by cable 4 extending upward from the car 3 in the shaft 1 about drum 5 'to idler 6 and then'to counter weight 7. In the operation of this elevator car.' to shift it from landingto landing in shaft 1, there is herein 'provided an alternating current electric motor 8 having on its shaft 9 Hy ball governor' 10, brake drum 11, and worm 12. This worin 12 is in mesh with worin wheel 13 on shaft 14 carrying the drum 5.

As an instance of-operation'it is herein shown that the car is to be shifted downward in the elevator shaft 1. controller 15 may be shifted in the car so that its upper portion swings to the left having its contact 16 still in connection with a terminal 17. This terminal 1 7 has line 18 therefrom through emergency switch 19 in the car 3, thence by line 20 through upper overtravel switch 21,*thence by line 22 to lower overtravel switch 23 and therefronrby line 24 to power supply line 25.

This controller 15l has remote from v.the contact 16, contact 26 which, in the shifting of the top 4of the controller'l to theleft, is swung to the right but still 'remains on terminal 27 connected by line 28 extending about coil 29 of switch 30 and extending therefrom by line 31. This switch 30, cuts out the `.brake releasing coil Whe-never the To this end 1922. Serial No. 559,173.v

:of the cardue to the line 39 connected to thecar 3 and about vpulle 'in'the'top of the' Sheff v11 and thence 'a out 'pulley "41'v in the. bottom 0f .the elevator shaft.- AS lang as the car 3 travels'in the elevator-'shaft `1 4at Y' thelrate of 4speed below' 'the clit'out of'ths tly ball. governor 38,.' .theswitch Eat this gov- 'ei'nor-remains' closed and `theffcurren't' from "tlie line 37- passs therethrough andI thence by line4 21to'thve-'uipp'ei` overtravelswitch 21 thencev byline 43'l'to 'the lower overtra'vel switch 23, thence by line to power supply '.li11e'45. 'y I- ,"In'j shifting i this"controller `15 from its:v neutral position fordowndirection travel to `lthe left as totop contact, this"con tact 16 is 'in' connection 'I with terminal 46 having 'line.' 47'.'thrughresistance' 48 and-` line 201 to-sw'itc'h 200 'atl'.y .balliv governor 10 on the :sl 1a. f 't'9. ',At thestarting position of the car, this switch 200 is normally-open.

' From; this switch'200iextendlines 202,108,

87,188, onl the 'side of the direction switches to receive power.`froxn the line 25 after' thel direction switches are thrown.' 'The other Contact 26 has connection'therefroin by terminal 71,'line 70, switch 55, line 69,?co'ntact 68, line 67, resistance 66, lines 65, 49 to switch 50. From this switch 50 extends line 51 to receive power from line 57 after the direction switches are thrown.

At this first position of the-controller. i5 as to the Contact 16 being in connection with the terminal 46. the remote contact 26 is shifted to cover the terminal 53 in connection by line 54 throughvdown limit car carried switch 55, thence by line 56 to power supply line 57. i 1

In parallel with thel switches 200, 50, at the speed responsive 'device v10, `which switches 200, 50, are normally'open. at low speed, there iswbranch 62 from the, line 201. This branch 62extends to =rlnotor 59 which is a switch operatin device of rotating field magnet type .for e ecting the operation of the direction switches. l This line 62 in extending to this motor 59 is to winding 61 of a Y tield with winding'GO having therefrom liue 5`8'e` .tel iding to the line 31. This mot-or 59 has in addition to the windings (S0, (i1, a third winding (53 connected by line 64 to line to resistance (5'6 thence by way of line G7 to terminal (58 adjacent the controller' contact 1G, thence by way olt line (39 through lower limit switch 55 in the eleva'- tor .car 3, thence by way of line to terminal 7l as a second tei'ui'nal adjacent this controller 15 to he engaged bythe contact .at the secondposition .ofshifting and at theftir'st real position of operation in the shifting ot this controller 15, This position o f the controller 15 in swinging the contact 26 to coverthe Contact. 71 is such that the tional,terminals. There is accordingly this intermediate position in the shifting of the controller 15 ,whichposition brings about the l( )peiation of the direction switches.

vThis operation ot the direction switch throwing motor 59 starts the inotornswitch shaft 72 .carrying cai n 73 for throwing switch 74. With the direction switch 74 riw shifted for down direction travel, it is to he borne in mind that the, mainswitchoperating device o i lnotor 75 still idle. has its shaftl 76 with c am 77 thereon holding norinally closed low speed main switch 78.

Thismain switch 78 accordingly is in posi- Ition to connect the power supply line 45 with power ,siipplyline 79 which has branch 80 extending to slow speed accelerating switch motor '81.v At said slow speed switch or rotary magnet deiice181. this line 80 is connected to winding 82 having Y connection with winding 83, with line 84 from this.

motor.81 .topower line 85 extending to the slow speed main switch 78 where it is there connected by this closed switch with the power vsupply line 52. This torque motor slow speed accelerating switch operatingr device 81 has a third winding 8G conncctedby line S7 extending to power line 88 connected by the closing ot the down direction switch 74 with power supply line 25. Accordingly the three phases to this motor 81 are now energized and thc shaft 89 of this motor 81 is rotated to drive pinion 90 in mesh with gear 91 for two to one speed reduction operation of the shaft 92, the cam 93 thereon throwing switch 94.

Inasmuch as the low speed main switch 78 is normally in or closed, this does not mean that the motor 8 is energized. Ener- Y gizing of the motor 8 does not occur until the direction switch 74 is thrown. As this direction switch 74 is thrown, power Supply line 57 is connected topower line 52 extending to low speed main switch 78 where this power line 52 is connected to power line 8 5. This line 85 extends toresistances' 95, 96, 97, :indthence by line 98 to winding 99 at the inotor `8 This normally closed low speed inaiii switch is accordingly normally Learner ing to resist-ance'105 and thence by line 106 to third 'slowspeed winding 107 at the motor 8. v Accordingly at once the direction switch 74 is thrown in under the circumstances that the low speed main switch is also previously closed or normally closed .thereis energizing lof 's'low speed windings n 99,104. 107, of the motor 8. Vupper contaetJG does not cover any addi- Simultaneoiisly with the energizing of the three sloii1 speed windings of the motor 8 due to the closingl of the direction switch 74 and the energizing t'if'tliel slow speed acceleration operatingdevice 81, there is'release ofthe brake .at the dr'ui'n 1 1, Fronithe line .87 eittends line to switch 'B0- where -it is connected hy th e 4closi'n ofthijs switch 30 with the line 109 exten ing past brake coil resistance 110 and thence by line'lll to brake coil 112. From'- thefdirection switch'haying therefrom line 5.2 an'd l i11,.51 thereis branch line 113 connected byfthe closing of the switch 30 with lin'e 114 through vbrake coil resistance 115 adntlience byline 11G to the brake 'coil'1 1 7. rom"these brake coils 112, 117, extends lii`i e 118 to line 44 and thence to the power supply line 45. The shaft 9 is accordingly released and the in tor is ready to start on its slow speed windings effecting driving of the elevator car 3 through the action of the rotation of the dr'uin 5. Simultaneously the motor 81 starts to rotate the shaft 92 in effecting closing of the switch 94.

As thisshaft 92 starts to rotate and in effcc-ting lirstthcclosing of the swich 94, this switch effects the connecting of the power supply line 85 with line 119 to cut out resistance 95 and simultaneously connects power supply 79 to line 120 to cut out the resistance 100. The further rotation of this shaft 92as driven by the motor 81 then et- {ccts through the cam 121 the operation of the switch 122, 'a time interval after the operation of the switch 94. This switch 122 hy line 123 effects connection of the line 119 to theline 123 toby-pass resistance 96 and simultaneouslythrough the line connects line 124 toshort out resistance 101. There is accordingly left in, as cu'rrentflow modifyingineans, onlytlie permanent resistances 97,- 102` 105, in the slow speed windings 9 9, 104, 107, of the n iotor'B. Theseperinanent resistances seryeto cushion the stopping of the -Inotcir.` At installation these resistargces may beregulated to conform to the conditionsdesired in opertion for sncli specific main switch operating motor 75. neously this-controller 15 has 1ts contact 26 conditions with great nicety. In this operation the controller may be thrown at once to high speed for a smooth pickup while in shutting off the motor lthere is auton'iatically an introduction of the slow speed resistances for cushioning the stopping of the motor.

travel of the elevator car 3, the contact 16 comes to the terminal 125 connected by way of line 126 through the emergency switch 19 thence by line/ 127 5to winding128 of the Simultaextend to terminal 129 thus connecting by .way of. linel .130 through the down limit switch =55-on the car 3 thence by line 131 to interlock .132 on up direction switch 33 which is-closed-because thei'operationof the `sha'ft-72 has shifted the cam 73 and closed the down direction Yswitch 74. Accordingly with the switch 133 open and the interlock l132 closed, :the line 131 is connected by line :134 towinding 135 of the switch operating motor 75. "The third winding136'for this switch operating motor is connected by Yline 137 to the -line 31. This switch operat Aing motor 75 is now energized and it shifts due to the opening of the main low speed switch 78. As this high speed main switch 139 -is cut. in, it connects thepower line 52 with power line 140 extending to high speed winding 1417at the motor 8. Simultaneously this high speed main switch 139 connects the power supply line 45 with line 142- extendingr to winding 143 at the motor 8. The down direction switch 74 has connected the power snpply line 25 with the power supply line 88 and simultaneously itl is effective in coi'inccting the power supply line 57 with the power line 52. From power line 88 extends line 144 to t-he third high speed winding 145 at the motor 8.

The supply line 142 has branch 146 extending to high speed acceierating motor 147 where it is connected to winding 148 therefor. From the switch 139, line 140 has branch 149 extending to this high speed accelerating switch motor 147 where the line 149 :connects to winding 150. The power line 88 has branch 151 extending to the third winding 152 of this rotating field magnet or switch operating device 147 having shaft 153 carrying pinion 154 in mesh with two to one speed reduction gear 155 for rotating shaft 156.

The winding 141 atthe motor 8 has therefrom line 157 extending to resistances 158, 159, 160, 161. The winding 143 has extending from this motor 8 a line 162 extending by way of resistances 163, 164, 165, 166. The third winding 145 at this motor 8 has a line 167 extending therefrom, thence by way of resistances 168, 169, 170, 171. These Series of resistances are terminally connected by line 172. Accordingly these resistances are outside of the motor and the Y winding for this motor 8 for high speed operation has its junction exterior the motor with these resistances therein. Accordingly as the high speed .main switch 139 is thrown in the high speed windings 141, 143, '145, are energized-with .considerable resistances in series with each thereof. The simultaneous energizing of the motor 147 serves to operate the shaft 156 carrying cam 173 effective tooperate in the first' instance switch 174. :Thisswitch Y174 through lines 175, 176, 177, is effective for Acutting out the resistances 166, 161, 171.

In the final arc of travel of this shaft 156 x through cam .188, thereon it effects closing of switch 189 and thereby connects directly lines 157, 162, 167, and cuts out the final and all of the `resistances in the.drawn out junc- -tionbetween the windings 141, 143, 145. The

final resistances thus cut out are 163, 158, 168.

The rate of rot-ation of this shaft 156 may be regulated through a dash pot mechanism. In the present embodiment thereof there is Vmounted on the terminus of the shaft 156, a

disk 190, from which extends a flexible connection 191 to counterwcighted piston 192 extending into dash pot 0r cylinder 193, the

'leakage of which may be adjusted by means Vof valve 194. On the disk 190, is disposed a }nojec.tion` stop or lug 195, which, in the rotation of the shaft 156 in either direction thereof comes into stop relation with a fixed abutment 196.

The rotation of the accelerating shafts 156, 92. as herein provided may approximate 120O in each'direction or a total of 240. The cams for throwing the accelerating switches 'are bilaterally symmetrical so that the shifting of the switches voccurs in the same sequence regardless of the direction of rotation of the shafts 92 or 156.

1n the shorter are rotation of the shafts 72, 76, there is a coupling with a pair of counter lil) weights 197, 198, which are to be overcome in the throw of in each direction and these conntcrweights normally set the devices, as do the countervveights 193 for the shafts 92 and 156. 'lhese counterweights 197, 19S. stop against fixed abutment 199.

it is to be noted that interlock 132 at the up direction switch 133 is always in when the down direction switch 74 is closed. Accordingly there may be no operation of the main switch operatingr motor from low to high speed until after the direction switch' is thrown for such desired direction o1 operation. This a safety device prccluding throwing of high speed connection in reverse direction.

Assuming that the high speed of rotation of the motor 8 is 1200 R. l. M. and that the low speed of rot-ation of this motor 8 is 300 R. P. M. The Slow speed governor may be set at say 450 R.. P. M. to close switch 50 as well as switch 200. .Anicordinglyv as long as the motor 8 is operating at about 450 R. P. M., the switches as controlled by the {ly-ball governor 10 are closed and at lower speeds are opened.

As long as the controller 15 is in position for drivingT the motor 8 through its high speed winding, the operation of the motor will be entirely independent of the position of the switches 50 and 200. .After the motor 8 has reached a speed sutlicient to cause the governor l0 to close these switches, however, and the controller is then returned to neutral position, the direction motor 59 will still bc held in as long as thc switches 50 and .200 remain closed.

lVith the controller 15 at neutral position, the high speed main switch 139 is open and the low speed switch 7S is closed. This holding` in of the direction motor 59 is effected by the switch 50 held closed by the `governor 10 for connecting the lines 49 and 51 to the windings 61 ot the. motor 59. The switch 2.00 is held closed by the governor 10 through lines 201. 202, and serves to conncctthe line G4 to the windingr G3 of this direction motor 59. 'lhc third winding 60 on this direction motor 59 is connected by the line 58 through the door interlocks and the sa fctv devices, thence by line 44 to the power supply line 45. Accordingly as longr as the speed of the motor S is above the rate of speed for the openingr of the switches 50 and *.200 on the governor 10. there is a holding;` in of the windings 99, 104. 107, of the slow speed windings of the motor 8 together with the permanent resistances 92, 97. 105, in series therewith. There is thus a generator load upon this motor 8 to act. as :in electric brake in retarding or slowing up the speed of the shaft 9.

Furthermore in the embodiment as herein disclosed, this generator braking action as brought about through the position of the governor 10 in maintaining closed the switches 50, 200, may occur automatically at a time before the setting of the brake upon the drum 11 if the controller 15 is offcenter sufficiently for the contact 26 to're'aeh the terminal 53. In suche-vent the'switches 80 f are held closed and current is' provided for the coils 112, 117. As soon fas the governor A 10 opens the switches ,5G-and. 2.00 the direction motor is deenergized and withfthe con'- tact 16 of the controller 15 olil the terminal .stead of being thrdugh the-downlim't'switch 55 on the car 3, suchfa're through u'pp'erlixriit switch 203' on. the car='3.1' 'i r The resistances 48,66' have-peculiar value as safety features inthe-combination herein disclosed. .One of these features'is ltha-t 'ofan interlock, which interlock is'of anelectrical nature insteadof a mechanical-character. In reversible motor operation, more particularly in elevatorpractice, man'yctimes the operator instead of: pulling the 'control1er15 to center will pull it past center for reversal. In the combination herewithythevspeed.governor 1() holding the direction switch in, operates upon the reversal of the controller 15 to ermit current flow by way of lines 47 or 67 liaving the resistances 48, 66.` These resistant-es are of such strength as to keep down any excessive or large amount of current flow which might arise from a shorting between phases due to the reversal of the controller as described. This means there is no excessive heating due to the reversal of the controller when the elevator car 3 is under way so that the governorlO is in for assisting in stopping the elevator by the generator action, beyond its synchronous speed.

There is a further safety feature due to these resistanees 48, 66. In the event that the control governor should become stuck or the circuit of this governor switch in any manner be shorted or remain closed, these resistances 48, 66 are in parallel with the windings to the direction motor and slow speed windings of the elevator motor. Due to the very low impedance lof the primary windings of the elevator' motor, there is no't enough current passing to the direction motor or control torque motor 59 to be effective in operating this motor because the re'- sistances 48, 66 are relatively so higlr What is claimed and it is desired to 'secure by Letters Patent is:

1. A motor, a high speed lwinding therefor, a low speed winding therefor, acceleration resistances .inseries with the low speed winding, a hormally closed low speed main switch, a direction switch for cuttingI in power current to the low speed winding through said main switch, a permanent resistance in Series with the low speed winding for cushioningthe stoppingr of the motor, switches for cutting out the vacceleration resistances, and a controller for the switches.

2.- A reversible alternating current motor having a high speed winding and a low speed winding, a normally closed low speed main switch, a direction switch for cutting in power current to the low speed winding through said main switch, and a permanent resistor in series between said main switch and saidA motor.

3. A reversible alternating current motor having a high speed winding and a low speed winding, avnormally closed low speed main switch, a -direct-ionfswitch for cutting. in powerfcurrentxto fthe low speed winding through said main switch, and a permanent resistor iii-series with the power circuit.

.4. A reversible alternating` current motor havinghigh speed connections and low speed connections, ai. normally. closed low .speed main switch, a direction switch for cutting in power current through said main switch to the low-speedconnections, and a permanent resistor inv-series with the low speed power'circuit..

5. yAn alternating current'motor having a highspe'edavinding and a low speed winding, a :normally closed -low speed main switch,"and afpermanentresistor 1n series between said main switch and said motor..

6. An alternating current motor having a high speed win-ding and a low speed winding, a normally closed low speed main switch` and a permanent resistor in series with the power circuit.

7. An alternating current motor having high speed connection and low speed connections, a normally closed low speed main switch, and a permanent resistor in series with the low speed power circuit.

8. A reversible alternating current motor having high speed connect-ions and low speed connections, a normally closed low speed main switch, a direction switch, a controller, and gravity operated means for establishing and other automatic means for maintaining a low speed power connection when, with the motor operating at high speed, the controller is shifted to any other position.

9. A reversible alternating current motor having high speedconnections and low speed connections, a switch for each of said connections, the switch for the low speed connection being normally closed, a controller, and a speed responsive device for maintaining a circuit through a low speed connection,

when the controller isshifted from motor actuating position to stopping position.

-' 1U. A reversible alternating current motor having high speed connections and low speed connections, a switch for each of said connections, the switch for the.1ow speed connection being normally closed, a controller, and a speed responsive device for maintaining a circuit through a low speed connection when, with the motor operating at high speed, the controller is shifted to any other position.

1l. A- reversible alternating current motor having high speed connections and low speed connections, a normally .closed low. speed switch, a direction switch, a controller, per- \manent current flow modifying means in the low7 speed power circuit,'.and means auto- -inaticallyi maintaining .a low speed power connection when, with the -inotor-ioper'ating at high speed, the controller is shifted to any other position. i.

12.- A. reversible alternating current motor having high speed 'connections and low speed connections, a switch-for each of said connections, the switch for ithe1lowspeed connections being normally closed, a controller, permanent current How modifying means in the lowspeed power circuit, and a speed responsive device for maintaining a circuit throughfa low speed connection when the vcontrolleris shift-ed from motor actuating position to stopping position. 13. A reversible alternating current motor having high speed connections andlow vspeed connections, a'switch foreach ofsaid-connections, the switch `for thelow speed connectionsbeing normally closed, a controller, permanent current -flow modifying means in the low speed power circuit, and a speed responsive .device for maintaining a low speed-connection when,\with the motor operating at a high speed, the controller is shifted to any other position.

14. A motor, a high speed winding therefor, a low speed winding therefor, permanent and acceleration resistances for the low speed winding, a normally closed low speed main switch with said permanent resistance in series between said switch and the motor, a direction switch for cutting in power current to the low speed winding through said main switch, switches for cuttingr out the acceleration resistance, rotating field magnets for throwing the switches, and a controller for the magnets.

15. A motor, a high speed winding therefor, a low speed winding therefor, resistance for said low speed winding, switches for the windings, a controller for the switches, a .rake for the motor, and automatic means for holding the low speed winding and its resistance in .and additionally sett-ing the brake with the controller in off position.

16. A reversible'alternating current motor,

direction switches .for the motor, a rotary actuator -or =t he direction switches, a controller for said .actuator and means preclud- .ingfthe shifting of said actuator by a reversal of the controller while the .motor is -operating above a predetermined speed.

1.7. A reversiblelalternating currentmotor, -direction switches 'rfor .the motor, a .poly- .phase .rotary actuator for the direction switches, .a polyphase controller for said actuator, and .means precluding 'the shift-ing of Saidactuator by a reversal ofthe controller while the .motor .is operating above a predetermined speed.

f18. A -two-speed .reversible .alternating current motor, main and direction .switches `there-for, a. polypha-se` rotary .actuator for thefdiieetion switches,.af.polypha se controller for `said actuator, and ,means :precluding the shiftingiof said.actuatorfbyza-reversal of the controller while thelmotor is .operating .above a predetermined speed. .19. Axreversible alternatingcurrentmotor, direction switches Ifor .ther-motor, a poly- :phase rotary .actuator :for-'the direction sirtitcheg a polypha'se'controller for .said actuator, speed responsive means precluding the Ashitting o said actuator :by a reversal of 'the controller .while the motor is operating above-a predetermined speed, and resistaneefimeans-iin fthe. controller circuit lprecludingthe.. short'. cireui'ting. of. the same 'under such fconditions.

Q0.. Areversible nlternatingfcurrent motor havingshighzspeed .connectionsandlow speed connections, switches for said connections, directionfsw-itches for t-helmotor, a -polyphase rotary :actuators-for thedireetion switches, a polyzphaselcontroller -for said actuator, speed responsive .means precluding .the shifting of sa itl actuator .f byv a :reversal of lthe vcontroller while :the motor Asfop'erating above .a predetermined speed, endl-resistance means in the controller .circuit ,precludin'g the short circuiti-ng .of 4fthe .same under such condi tions.

Q1. A .motor,.a -po-wer current supply for the motor, fafhiglrspeed winding for the motor,` a low :speed iwinding for the motor, a plurality-of 'acceleration .resistances in series with the.lloivspeedfwinding, a plurality of acceleration resistances in series with the high -speed winding, switches for the acceleration `i'esistances, high and lowspeed main switches, .direction tswitches, four rotating lield magnets Ifor. :operating -said switches, and acontroller for determining the sequencc'o-f'operation lofsaid magnets, said acceleration .switch operating l.magnets being energi-zedfbyithe .power current supply only as supplied tothe motor,xand 'the respective windings ,and `their :respective resistances b'eing `i-n 1parallel 'wit-htheurespective magnets.

,22.A.niotor, .a .high-.speed :winding therefor, a flow=speed Iwinding itherefor, separate 'f acceleration resistancesrfor lsaid windings,

switches for the respective acceleration re- -sistances, a normally closed main switch for the. low speed winding, a main switch for the high speed winding, direction switch means means as operators-for the respective acceleration resistance switches, .power means 'for the directidn switch means, m'eans for clos- .ing the high speed main switch-coacting simultaneously tor opening-the low speed main switch, .and a controller effective through said last-mentioned means for directly operating saidilowand high speed switches.

23. A reversible motor,.a high speed winding therefor,.a lony .speed winding there-for, a normally closed main switch :for the low speed winding, an additional .main .switch for the high speed winding, direction switch means, a main switch .operating device :for .-both ofsaid switches, an .finterlockcontrolled by the direction-switch.means, :and a controller rendered, 'by-said interlock, ineffective. for supplying power `current to the motor by way of ithehigli speed main switch, when the controller is shifted from a posit-ion for operation ofthe motor in -one directionto a .position for operation ofthe motor .iii v'the other direction, until the direction .switch means isoperated. l .A polyphase -iveversible motor, a high speed winding therefor, alow speed-primary winding therefor, permanent torque decreasing means ffor :said lowv speed winding, switches for the windings, aupolyphase controller2forfthe switch-es, and a speed responsive device fforjholding-the flow speed `winding l'and its permanent torque decreasing means in circ-uit, with the controller shifted backfroma position forflow speedoperation of the motor in a given direction, as longr as the motor is still operated -in that. direction above a prt-determined speed.

2:3. A motor, a high speed windingtherefor, a low speed winding therefor, resistance for said low speed -\\'indiiig, a normally1 closed main switch for the low speed winding, an additional switch for the high speed windings. operating means for the switches, a controller directly effective by operating the switch operating means at lall times, and automatic means for holding the low speedwinding and its-resistance invciroiiit.

26. A motor, va high speed winding-therefor, a-low speed winding therefor, resistance for said low speed winding, a normally closed main switch for-the' low speed winding, an 1additionalswitch for the 'higli speed windings, -a controller for 'the switches, a brake 'for the motor, and automatic means for'holding vvthe vlow speed winding and its resistance-in circuit and vadditionally sett-ing the 'brake wit-hilthe controller-ien off position'.

271; The combinationwith'a-n elevatonofsa Asequence ofrswitch'ijiiiingiintl'closiiig -s y I 1 controller. 28. The combination avitlr'an'ielevator, ot

with the con'trplle' interlvc'kfpij cludiI he'iitle ng oft troller'fet''ctiifcufi .pertng a pee'd switclifif said /cn't olleri's shifte'dtfrdin a positionutoropera ionjothe motor in one directioto a-'posi ion `fdroperation of the motor in the other direction, when the motor is operating. v

29. An elevator control .system having a multi-speed polyphase electric lnotor provided with a primary winding having a Y- junction brought out of the motor, a polyphase electric current supply for the motor, said system embodying acceleration resistances between said junction and the windings, a main switch, acceleration switches, a torque motor for operatingr the main switch, a torque motor for operating the acceleration switches, and a controller for said motors, establishing operatingr connection for the :wceleration torque motor, to be completed hy the operation of the main switch of the other torque motor, Suid acceleration .switch torque motor being operable by said controller only when all phases ot the current are supplied to the power motor.

30. A control system comprising a polyphase electric motor provided with a primary winding having a permanently closed Y-junction brought out of the motor, aY polyphase electric current supply for the motor, said system embodying` acceleration resistance between the junction and the winding, switch means for said winding remote from the junction, switches for the acceleration resistance, and separate power actuated dcvices for the acceleration switches connected on the same side as said motor, said devices for operating the acceleration switches being operable by the cont-roller only when all phases of the c urrentare supplied to the power motor.

3l. A control system having a pnlyphase electric motor provided with aprimary winding haviinor a permanently :closed Y- junction brought out ot' the motor, said system embodying acceleration resistance between lhe junction and each winding, sets of switches for cutting ont said resistances in sequence, an additional switch for thc motor, and separate power actuated devices for said setsof switches,- said devices being on the same' side of said additional switch as said motor.`

32. A reversible motor, direction switches for-thc motor, a common reversible actuator furthe direction switches, a` controller for said actuator, means l)y-passing-the controller and effective lo temporarily n'iaintain the position of the actuator, and resistance ineans'in the controller circuit, rendering said controller ineffective to Vreverse said act'uator4 while'the luy-passing means is ,effectivef l 33. A: reversible'alternating current motor, direction switches for the motor, a common reversible'polyphase actuator for lthe direction switches, a polyphase controller for said actuator; means by-jpassing?r the controller and effective to temporarily maintain the position of the actuator after the controller has been moved to shift said actu- 5'1" ator, and resistance means in two Phases of the controller circuit, rendering said controller ineffective to reverse said actuator while the by-passing means is effective.

34. A reversible motor, direction switches for the motor, a common reversible actuator for the direction switches, a. controller for said actuator, speed responsive means bypassing the controller and eective to maintain the position of the actuator until the motor has slowed down after the controller has `neen moved to shift said actuator while the hav-passingr means is eiective.

35. A lnotor control installation including' direction switches, conductor lines to said .switches for polyphase electric current, a direction switch operatingr motor, a controller for the motor` a speed responsive device for holding the direction switch in, and supplemental control means including resistances between the controller and switch operating means preclnding excessive cnrrent fiow arising from shortingbet-ween different phase conductor lines when the controller is reversed.

36. A main motor, a direction switch therefor, a direction switch operating motor, a controller for the direction switch motor, a speed responsive device for holding;r the direction switch in independently of the controller, and supplemental control means including resistance between said controller and the direction switch operating motor, and connections on the same side of said switch as the main motor for precludine lili) operation of the direction motor when the speed of the main motor is great enough to actuate said speed responsive device.

37. A ployphase motor control installation including conductor lines for different phases of electric current, a speed responsive device provided with a switch, a direction switch for the motor, a inulti-phase actuating device for the direction switch, and con ncctions from a plurality of conductor lines for different phases to said speed responsive device switch and said actuating device, said actuatingr device being connected on the same side of the direction switch as .the motor.

3S. A multi-.speed motor` provided with high and low speed primary windings, switches for the windings, a controller vfor the switches, conductor lines for dill'erent phases of electric current,multiphase actuating means .for the switches, and a speed responsive device for ,holding in the low speed windings, when the controller is shifted to stop the motor, whiletthe motor .acts as a generator land electric brake, until said motor approaches synchronous speed, said device including switches in a plurality of said conductor lines for different phases connected to said actuating means.

39. A multi-speed motor provided with high and low speed primary windings, conductor 4lines for different phases of electric current, .a torque decreasing permanent rosistor in series .with said low spccd windings, switches for the windings, a controller for thel switches, and a speed responsive device for holding 'in the low speed windings and said resistor, when the controller is shifted to stop the motor, while the motor acts as a generatorfand electric brake, until said motor approaches synchronous speed, said device including switches in a plurality of said conductor-lines for different phases.

40. An alternating current. power motor having high and low speed connections, polyphasel supply lines therefor, a line switch for said motor, a resistor for each speed, a set -of acceleration switches for each resistor, means includingJ a torque motor and rock shaft for operating the line switch, silnilanoperating means for each set of ac- ',celeration switches', -control means ffor the line switch torquel motor, and means for energizing thetorque motors for the acceleration switches onlyv when all phases of the current are supplied to the power motor.

In witness whereof I affix iny signature.

ERNEST B. THURSTON. 

